如何使用 WIN32 API for C++ 更改文本的颜色和大小？

Question

I have been searching for days for an answer to my question, but I can't seem to find any solution which works for me... Possibly because I may be thinking of this all wrong.

I am trying to create a basic window which pops up a string of text in a large red font using WIN32 API in C++.

I have tried using the WM_CTLCOLORSTATIC control within my WindowProcedure, but I can't seem to get the text to change color. However, I am able to create text with the WM_CREATE, so I am confused on what I am doing wrong...

Here is what I have written so far.

#include <iostream>
#include <windows.h>

LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);

HWND textfield;
HDC hdc;

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR args, int nccmdshow) {

    WNDCLASSW wc = { 0 };

    wc.hbrBackground =  (HBRUSH)COLOR_WINDOW;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hInstance = hInst;
    wc.lpszClassName = L"myWindowClass";
    wc.lpfnWndProc = WindowProcedure;

    if (!RegisterClassW(&wc))
        return -1;

    CreateWindowW(L"myWindowClass", L"My Window", WS_OVERLAPPEDWINDOW | WS_VISIBLE, 500, 200, 1000, 500,
        NULL, NULL, NULL, NULL);

    MSG msg = {0};

    while (GetMessage(&msg, NULL, NULL, NULL)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return 0;

}

LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {


    switch (msg) {
    case WM_CREATE:
        textfield = CreateWindow(L"STATIC", L"DEBOODAH!", WS_VISIBLE | WS_CHILD , 500, 100, 300, 25, hWnd, NULL, NULL, NULL);
        break;

    case WM_CTLCOLORSTATIC:

    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProcW(hWnd, msg, wp, lp);
    }

}

Any help would be greatly appreciated!

Answer 1

The WM_CTLCOLORSTATIC message gets a device context handle ( HDC ) in wParam. Here's how you use it:

case WM_CTLCOLORSTATIC:
    SetTextColor((HDC)wp, RGB(255, 0, 0));
    return DefWindowProcW(hWnd, msg, wp, lp);

The text size is a whole different story. Once you create the static window, you have to construct a font and feed it to the static:

case WM_CREATE:
    textfield = CreateWindow(/*...*/);
    HFONT hf = CreateFont(/*size=*/-12, 0, 0, 0, FW_NORMAL, 0, 0, 0, ANSI_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH, L"MS Sans Serif");
    SendMessage(textfield, WM_SETFONT, (WPARAM)hf, 0);
    break;

Painting your own text, as Sebastian suggests, is also possible.

Answer 2

You could read about drawing inside a window.

Typically one would put the following code inside case WM_PAINT:

case WM_PAINT:
    PAINTSRUCT ps;
    HDC hdc = BeginPaint(hwnd, ps);
    // draw here
    EndPaint(hwnd, &ps);

With the hdc handle you can call functions like TextOutA/TextOutW, SetTextColors and others

You create a 2nd smaller window inside, when the parent window is created (WM_CREATE). This smaller window can be preset only rudimentarily. Try to leave it away, when painting with WM_PAINT.